Added standard Methods to SVG Elements

https://prototype.lighthouseapp.com/projects/8886/tickets/1655-include-svgand-others-elements-support

I've added some changes to dom.js to add the standard methods to SVGElements, but didn't know if this was something to address.

I've tested on IE6-IE10 it fails silently on IE6-8 and works on IE9 and 10

also tested on Firefox/Chrome/Safari

If SVGElements should not have these methods or need a smaller set of methods I can do that too